Paleoenvironments and Hydrocarbon Potential of Upper Cretaceous Shales in Agbabu-1 Well, Dahomey Basin SW Nigeria

Upper Cretaceous shales partially exposed in the northern fringes of the Dahomey Basin are well developed in the subsurface in Southwestern part of the basin where Agbau-1 well is sited. These shales were evaluated in respect to their paleoenvironments and potentials for hydrocarbon using foraminiferal assemblages, biomarkers and Rock Eval pyrolysis studies. The dominance of benthonic foraminifera species suggests a shallow marine environment and high percentage of calcareous to arenaceous benthic www.eujournal.org 195foraminifera indicate high water salinity and hypersline environment. Dysoxic oxygen condition is also prevalent probably because most of the benthic foraminifera recovered are epifauna that live in a reduced oxygen condition. 1.90 wt%, 244 mgHC/gTOC and 429℃ average values of total organic carbon, hydrogen index and Tmax reveal that the Upper Cretaceous shales have relatively fair to good organic matter, predominantly Type II-III kerogen and currently immature. Though three is a trend of an increase in maturity down the hole. All the steranes have uniform distributions (C27>C28>C29), suggesting a relatively higher input from the marine red algae and a low level of land plant contribution to the source organic matter. Pristane/phytane ratios and C29/C27 steranes confirmed the organic matter type to be a Type II/III and anoxic source rock depositional condition as well as a reducing diagenetic system in the sediment water column. The Upper Cretaceous shales in Dahomey Basin can be targeted for exploration as an unconventional petroleum resource.

Characterization of PAHs Trapped in the Soot from the Combustion of Various Mediterranean Species

Climate change causes more frequent and destructive wildfires even transforming them into megafire. Moreover, all biomass fires produce emissions of carbon compounds in the form of soot to the atmosphere with a significant impact on the environment and human health. Indeed, the soot is causing the formation of PAHs from (a) the high temperature thermal alteration of natural product precursors in the source organic matter and (b) the recombination of molecular fragments in the smoke. However, these molecules are known to have carcinogenic effects on human health. It is therefore interesting to quantify the 16 PAHs concentration extracted from soot emitted in open diffusion flame of biomass combustion. To achieve this objective, an analytical method developed for the study of kerosene combustion has been adapted for soot from biomass. This new method allowed to quantify the 16 PAHs defined as priority pollutants by the US EPA for their carcinogenic mutagenic effect and on human health.